A typical control panel for earth moving equipment comprises buttons for operation by fingers and one or several displays for visual presentation of results of adjustments or measurements. Furthermore, there is frequently a physical key to be inserted into a lock to initate operations. This lock is an important safety provision, to prevent accidental use by non-professionals and to prevent theft. Such control panels have to endure very harsh conditions ranging from freezing cold, via extreme humidity to sand and dust. For these reasons, constructions are generally known where the control panel is removable and is only fitted in a cradle or receptable on the equipment when it is to be used. The electrical connections for power and data are made by means of plugs that interface with sockets that may be closed by a lid when not in use. However, it has turned out that there is considerable wear on contact parts, and in particular humidity works against reliable connections, which means that although the control panel may be kept indoors when not in actual use, it will with time still become unreliable in practical use. Some of the wear is accelerating and corrosive even though the power supply might be made by AC, due to rectification in corrosive surface layers. In particular with earth moving equipment this may have a serious influence on the safety or leave the equipment out of control in awkward positions.